The document discusses key principles of adult learning theory, including that adults: are autonomous, goal-oriented, relevance-oriented, and draw from life experiences; are practical learners who need respect; and are motivated both internally by cognitive interest and externally by factors like relationships, expectations, and advancement. It also outlines barriers to adult learning like lack of time and money, and strategies instructors can use to aid retention, motivation, reinforcement, and transference for effective adult education.